The Earth Science Picture of the Day (EPOD) highlights the diverse processes and phenomena which shape our planet and our lives. EPOD will collect and archive photos, imagery, graphics, and artwork with short explanatory captions and links exemplifying features within the Earth system. The community is invited to contribute digital imagery, short captions and relevant links.

Ohio Lunar Halo

The photo above shows an eye-catching lunar halo as seen from my home in East Dayton, Ohio, on September 30, 2012 – two days past the Harvest Moon. The view is toward the southeast. Randomly oriented, pencil-shaped ice crystals in the thin cirrus overcast triggered this classic 22 degree halo. As moonlight (or sunlight) passes through a side face of these crystals it’s refracted 22 degrees from the initial angle of incidence before exiting through an alternate side face. Because Mother Nature is sometimes surprising, I always go out at look at the night sky before I go to bed, even if the forecast calls for cloudy skies.